JPH11326300A - Liquid chromatograph - Google Patents

Abstract

(57) [Problem] To provide a liquid chromatograph capable of resolving pressure fluctuations exceeding a normal value range and automatically restarting analysis. SOLUTION: When a pressure fluctuation exceeding a normal value range is detected during the analysis, the discharge port of the liquid supply pump is connected to the drain by switching a drain valve, and the liquid supply pump is driven at a high speed for a certain time to perform a purge operation. Perform After that, return the drain valve and connect the liquid sending pump to the separation column,
The pressure fluctuation is monitored for a certain period of time. When the pressure fluctuation is within the normal value range, the sample is re-injected and the analysis is automatically restarted. When the pressure fluctuation does not return to the normal value range, an error message is displayed, the analysis is interrupted and the process is terminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid chromatograph in which various chemical substances are moved together with a mobile phase and separated and analyzed using a separation column.

[0002]

2. Description of the Related Art A conventional high-performance liquid chromatograph is provided with a pressure sensor for measuring the pressure of a mobile phase from a discharge port of a liquid sending pump, and monitors the pressure of the mobile phase.
For example, if bubbles are introduced into the liquid transfer pump and liquid transfer failure occurs, and a pressure fluctuation exceeding the normal value range, such as a sudden decrease in pump pressure or a rapid increase in pulsation, is detected, the device stops the analysis as an error. Or continued analysis as it was.

[0003]

When the pressure condition fluctuates suddenly, the reproducibility of data is lost. Therefore, even if the pressure fluctuation exceeds the normal value range, even if the analysis is continued, the data is not reliable. Then, after the operator manually performs a process for returning the pressure state to a normal state, it is necessary to restart the analysis of the sample in which the analysis has been interrupted or the sample which has been continued as it is, and this operation is complicated for the operator. Was.

Accordingly, an object of the present invention is to provide a liquid chromatograph capable of automatically restarting the analysis when the pressure changes suddenly.

[0005]

FIG. 1 is a block diagram schematically showing the present invention. The pump unit 1 includes a liquid sending pump 3 for sending a mobile phase to a separation column (not shown) for separating a sample, a drain valve 5 for switching a flow path from a discharge port of the liquid sending pump and connecting to a drain, and A pressure sensor for measuring the pressure of the mobile phase discharged from the liquid sending pump 3 is provided. The flow path between the liquid sending pump 3 and the separation column is provided with a sample introduction unit 9 for introducing a sample into the mobile phase.
A column oven 11 for keeping the separation column at a constant temperature and a detection unit 13 for detecting sample components separated by the separation column are provided. The liquid sending pump 3, the drain valve 5, the pressure sensor 7, the sample introducing unit 9, the column oven 11, and the detecting unit 13 are connected to a controller unit 15, and the respective operations are controlled by the controller unit 15. The controller unit 15 includes a CPU 17, a ROM 19 storing an operation program, and a RAM 21 for temporarily storing a detected pressure and the like.

At the time of analysis, the pressure fluctuation is monitored by the pressure sensor 7, and if a pressure fluctuation exceeding the normal value range is detected, the drain valve 5 is switched by the controller unit 15 so that the discharge port of the liquid feed pump 3 is opened. Connected to the drain, the purging operation of the liquid sending pump 3 is performed for a certain time.
As the purge operation, the liquid feed pump is operated at a high speed.
After that, the drain valve 5 is returned to connect the liquid feed pump 3 to the separation column side, and then the analysis is restarted if the pressure fluctuation detected by the pressure sensor 7 returns to normal. When the abnormality of the pressure fluctuation can be eliminated by the purging operation of the liquid sending pump 3, the present invention can automatically restart the analysis.

[0007]

FIG. 2 is a schematic structural view showing an embodiment. The mobile phase from the mobile phase bottle 23 is sent to the separation column 27 by the liquid sending pump 25. In a flow path between the liquid feed pump 25 and the separation column 27, a flow path from the liquid feed pump 25 is switched to be connected to a drain, and a drain valve 29, and a pressure of a mobile phase discharged from the liquid feed pump 25 is measured. A pressure sensor 31 and an autosampler 33 corresponding to a sample introduction unit for introducing a sample are provided. Liquid sending pump 25,
A pump section 35 is constituted by the drain valve 29 and the pressure sensor 31. Separation column 27 is column oven 3
7 and is kept at a constant temperature. Separation column 27
A detector 39 is provided at the outlet of the flow path, and is connected to the drain. Liquid sending pump 25, drain valve 29, pressure sensor 31, autosampler 33, column oven 3
The detector 7 and the detector 39 are connected to the controller 41, and the respective operations are controlled by the controller 41.
The detection signal from the detector 39 is sent to the data processing device 43, and identification and quantification of the detected peak are performed.

The operation of sample analysis according to this embodiment will be described. The separation column 27 is set in a column oven 37 and connected to a flow path. The controller unit 41 connects the drain valve 29 to the flow path, drives the liquid feed pump 23,
The mobile phase is sent to the separation column 27. The column oven 37 is heated to maintain the separation column 27 at a constant temperature, and the detector 39
After the detection signal from is stabilized, the controller 41 drives the autosampler 33 to inject the sample into the channel. A normal range of the pressure fluctuation is set in the pressure sensor 31, and the sample is separated from the separation column 27 while monitoring the pressure fluctuation.
And the separated component is detected by the detector 39. Detector 3
9 is sent to the data processing device 43 to identify and quantify the separated components.

FIG. 3 is a flowchart showing the operation of this embodiment at the time of analysis. This flowchart and FIG.
The operation will be described with reference to FIG. The sample is introduced from the autosampler 33 into the flow channel, and the analysis is started. Pressure sensor 31
To periodically monitor the pressure fluctuations in the flow path. If the pressure fluctuation is within a predetermined normal value range, the analysis is continued while monitoring the pressure fluctuation, and the analysis is terminated when the separation of the sample is completed or when a predetermined analysis time has elapsed.

If a pressure fluctuation exceeding the normal value range is detected by the pressure sensor 31 during the analysis, the controller 4
By 1, the drain valve 29 is switched to connect the discharge port of the liquid feed pump 25 to the drain, and the liquid feed pump 25 is driven at a high speed for a certain time to perform a purge operation. The drain valve 29 is returned, the discharge port of the liquid sending pump 25 is connected to the flow path, and the mobile phase is sent to the separation column 27.
Step 1 monitors the pressure fluctuation for a certain period of time. When the pressure fluctuation is within the normal value range, the sample is re-injected from the autosampler 33 to resume the analysis. If the value exceeds the normal range even after the purge operation, an error message is displayed, the analysis is interrupted, and the process is terminated.

In the case where the abnormality of the pressure fluctuation can be eliminated by the purging operation of the liquid sending pump, for example, when air bubbles enter the liquid sending pump, the analysis can be automatically resumed, and the operation can be performed automatically when there is no operator such as during unmanned operation. No need to interrupt analysis. As the drain valve, any switching valve such as a three-way solenoid valve and a rotary valve may be used. Further, the drain valve and the pressure sensor may be installed outside the pump unit, or may be built in as in the embodiment.

[0012]

According to the present invention, a drain valve is connected between the liquid sending pump and the separation column, and when a pressure fluctuation exceeding a normal value range is detected during the analysis, the drain valve is switched and the discharge port of the liquid sending pump is switched. Is connected to the drain, the purge operation of the liquid supply pump is performed, and then, after the drain valve is returned and the discharge port of the liquid supply pump is connected to the flow path, if the detected pressure fluctuation is within the normal value range, Since the analysis is restarted, the analysis can be automatically restarted when the abnormality of the pressure fluctuation can be eliminated by the purge operation of the liquid sending pump.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically illustrating the present invention.

FIG. 2 is a schematic configuration diagram illustrating an embodiment.

FIG. 3 is a flowchart showing the operation of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pump part 3 Liquid sending pump 5 Drain valve 7 Pressure sensor 9 Sample introduction part 11 Column oven 13 Detection part 15 Controller part

Claims (1)

[Claims] 1. A separation column for separating a sample, a liquid sending pump for sending a mobile phase to the separation column, a pressure sensor for measuring a pressure of the mobile phase discharged from the liquid sending pump, and a liquid sending pump. A sample introduction unit that introduces a sample into the mobile phase in a flow path between a pump and the separation column, a column oven that maintains the separation column at a constant temperature, and a detection unit that detects a separated component separated by the separation column. In a liquid chromatograph comprising: a drain valve for switching a flow path from a discharge port of the liquid feed pump to connect to a drain in a flow path between the liquid feed pump and the separation column; When the pressure sensor detects a pressure fluctuation exceeding a normal value range, the drain valve is switched to connect the discharge port of the liquid feed pump to a drain, and After performing the purge operation, after returning the drain valve connecting the liquid feed pump to the separation column side, to measure the predetermined time pressure variation by the pressure sensor,
A liquid chromatograph comprising a controller for restarting the analysis if the detected pressure fluctuation is within a normal value range.